Help with electroplating please!

I have a copper penny attached to the negative terminal of a 9V battery. I have a nickel (made of the metal nickel) attached to the positive terminal. I put this circuit in water. After 20 minutes, I notice that the nickel has orange deposits on it which I believe are copper.

Why does this work? It doesn't make sense to me. I thought copper had a positive charge and would not be attracted to another positively charged object.